The present invention relates to farm implements and, more particularly, to a quick-change seed metering assembly capable of sectional control.
Air seeders are commonly towed by tractors to apply seed, fertilizer, or micro-nutrients or any granular product to a field. For purposes of this application “seeding” shall include the application or deposition of any granular or particulate material onto a field. It is generally advantageous to tow an air seeder in combination with a tilling implement, one behind the other, to place the seed and fertilizer under the surface of the soil. An air seeder has as its central component a wheeled seed cart which comprises one or more frame-mounted seed tanks for holding product, generally seed or fertilizer or both. Air seeders also generally include a volumetric metering system operable to measure a fixed volume of seed per unit of linear distance and a pneumatic distribution system for delivering the product from the tank to the soil.
The volumetric metering system is configured for distribution of product from the tank to the distribution headers of the seed tubes. The metering system typically includes a meter roller assembly employing augers or fluted cylinders (meter rollers) situated in a meter box assembly secured below the tank.
Typically the meter box will have a series of outlets known as runs that each leads to the distribution lines of the pneumatic distribution system. The pneumatic distribution system generally includes an air stream operable to carry product metered by the meter roller assembly through the distribution lines to a series of secondary distribution manifolds (“headers”), which in turn distribute product to a group of ground openers mounted on the seeding implement operable to place seed in the ground. The ground openers are configured to evenly deliver the product to the span of ground (the “seedbed”) acted upon by the seeding implement.
One of the drawbacks of conventional meter roller assemblies is the difficulty and time required to replace the meter roller assembly in a meter box assembly. As a meter roller assembly will generally have a profile that is suited to a particular type or size of granular material, it can sometimes be required for a farmer to switch-out the meter roller assembly of a meter box assembly between seedings. For example, meter roller assemblies with extra fine profiles are typically used when applying micronutrients or very small seeds such as alfalfa, grass, canola or grain sorghum at very low rates. Fine meter roller assemblies are typically used to apply barley, oats, flax, millet and moderate rates of fertilizer. Coarse rollers are used for high rates of larger seeds such as corn and beans, and for solid seeding, and extra coarse rollers are typically used for larger and fragile seeds like peas and large beans as well as high rates of fertilizer. So as a farmer's seed and/or fertilizer requirements change so too may the need to replace the meter roller assembly with a more appropriate assembly. While conventional meter roller assemblies are generally interchangeable, the construction of such conventional assemblies can make it difficult to perform such a task.
Another drawback of conventional meter roller assemblies is the difficulty in achieving sectional control. Due to the increasing cost of seed and fertilizer, the agronomic disadvantage and waste associated with redundant application of seed and fertilizer, and the increasing size of seed drills, efforts have been made to selectively shut off the flow of granular material to selected distribution lines. Various approaches have been implemented to provide sectional control and with modest success; nevertheless, there remains a need for a meter roller assembly capable of providing sectional control.